The present invention relates to test weight assemblies for the testing and certification of material handling equipment. More specifically, the present invention relates to test weight assemblies for nuclear material handling, such as the handling of spent nuclear fuel casks and reactor components. Test weight assemblies constructed of water bags, concrete blocks, or buckets of scrap metal are impractically large and may be unstable. Furthermore, those systems may be inappropriate for use in a nuclear utility environment due to difficulties in decontamination and not being rated for seismic activity.